Thomas Alva Edison is an inventor. He spends 3 1/8 hours in the morning, 2 3/8
hours in the afternoon and 5 5/8 hours at night working in his laboratory. How
many hours does Thomas Edison spend in his laboratory?

Discuss
the problem to the pupils using guide questions.

Guide
the pupils in arriving to the correct answer.

Let
pupils discover the process of adding similar fractions.

Ask:
Do you know that Thomas Edison invented a lot of things that we use today? What
attitude do you think did he have to invent new things? Do you think he was
always successful?

Share
Edison’s famous quote: “A genius is 10% made of inspiration and 90% made of
perspiration.”

2. Exercise

Pair-Share
Activity. Find a partner and add the series of fractions.

a)
2/9 + 3 + 4/9 + 1/9 + 2 1/9 + 1 + 3/9

b) 2
+ 4 + 1/10 + 3/10 + 5/10 + 3 2/10 + 2 + 4/10

c) 1
+ 4/7 + 3 + 0 + 1 2/7 + 3/7 + 2 + 8/7

d) 8
+ 2/6 + 1/6 + 3 + 2/6 + 2 + 4/6 + 1/6

3. Generalization

How do we add similar fractions in
simple form? in mixed form?

C. Application

Thomas Edison wanted to invent a new
machine. Help him ass the materials he needed:

1)
2/4 m + 3/4 m of rope

2) 1
1/14 ml + 3 3/14 ml + 8 9/14 ml of He

3)
2/5 kg + 3 3/5 kg + 5 5/5 kg of nails

4)
1/10 tsp + 2/10 tsp + 12/10 tsp + 1 3/10 tsp of sand

5)
3/15 cup + 8/15 cup + 2 cups of acetic acid

IV. Evaluation

Give
the sum of the following fractions:

1)
2/5 + 2 + 4/5

2) 6/11
+ 7/11 + 8/11 + 9/11

3) 2
+ 3/15 + 3 + 4/15

Read
and write the correct solution

4)
Alexander Graham Bell, the inventor of the telephone needed the 1/8 m of copper
wire; 3 4/8 m of silver wire and 5 m of tin wire. How many meters of wire did
he need in all?

5) The Wright brothers used fuel to test their
newly-made air vehicle. They used 9 3/7 liters of fuel in the first try, 11 6/7
liters in the second try and 8 1/7 liters in the third try. How many liters of
fuel did the brothers use in all?